The cool kids usually listen to Urban or Rock music honestly.

You never hear a popular kid say, "Yeah, you heard that new Britney song?!"
But anyways, out of this list, Rihanna by
far. And that's why I love her. She's not one of those Pop stars that cater to just one audience like most of the Pop girls do. She's branded herself as a versatile artist that constantly reinvents herself that anyone can recognize and have at least few songs of hers on their iPod. And straight men love her because she puts out songs that aren't Pop-ish to the point where they sound girly.
And I know alot of cool teenage girls that love Katy Perry and Taylor Swift as well.